HL7 SIU_S26 (Patient Did Not Show Up) | Integration Soup HL7 Reference Guide

HL7 SIU_S26 Patient Did Not Show Up

The appointment time came and went, and the patient did not arrive.

HL7 message structure SIU_S12 groups and segments from HL7 v2.5.1 Hide structure

These are the generated groups and segments for the version selected at the top of the page. The article explains the workflow, and this panel follows the chosen HL7 version.

Message Structure

Segment	Name	Required	Repeatable
MSH	Message Header	Yes	No
SCH	Scheduling Activity Information	Yes	No
TQ1	Timing/Quantity	No	Yes
NTE	Notes and Comments	No	Yes
SIU_S12.PATIENT	Patient group	No	Yes
PID	Patient Identification	Yes	No
PD1	Patient Additional Demographic	No	No
PV1	Patient Visit	No	No
PV2	Patient Visit - Additional Information	No	No
OBX	Observation/Result	No	Yes
DG1	Diagnosis	No	Yes
SIU_S12.RESOURCES	Resources group	Yes	Yes
RGS	Resource Group	Yes	No
SIU_S12.SERVICE	Service group	No	Yes
AIS	Appointment Information	Yes	No
NTE	Notes and Comments	No	Yes
SIU_S12.GENERAL_RESOURCE	General Resource group	No	Yes
AIG	Appointment Information - General Resource	Yes	No
NTE	Notes and Comments	No	Yes
SIU_S12.LOCATION_RESOURCE	Location Resource group	No	Yes
AIL	Appointment Information - Location Resource	Yes	No
NTE	Notes and Comments	No	Yes
SIU_S12.PERSONNEL_RESOURCE	Personnel Resource group	No	Yes
AIP	Appointment Information - Personnel Resource	Yes	No
NTE	Notes and Comments	No	Yes

SIU_S26 notifies receivers that the patient did not show up for a scheduled appointment. This is not a cancellation before the visit. It is a status after the scheduled time, and it often drives statistics, reminder follow-up, resource release, missed-appointment workflows, and care-gap outreach.

S26 uses the shared SIU^S26^SIU_S12 structure. The generated panel below shows SIU_S12, while the event code tells the receiver this appointment is a no-show.

A small SIU S26 example

MSH|^~\&|SCHED|CITYHOSP|EHR|CITYHOSP|20260719124500||SIU^S26^SIU_S12|SIU260042|P|2.5.1 SCH|A100045|F100045||NOSHOW^Patient did not show^L|NOSHOW|OFFICE^Office visit^L|30|min|^^^20260719113000^20260719120000|||||12345^Careful^Clara NTE|1||Patient did not arrive by the clinic no-show cutoff. PID|1||123456^^^CITYHOSP^MR||Smith^Jane^Anne^^Ms^^L||19800314|F PV1|1|O|CARD^ROOM2^^CITYHOSP RGS|1 AIS|1||CARDREV^Cardiology review^L|20260719113000|30|min AIL|1||CARD^ROOM2^^CITYHOSP|20260719113000|30|min AIP|1||12345^Careful^Clara|CARD^Cardiologist^L|20260719113000|30|min

What systems do with it

The sender is usually the filler scheduling system or clinic workflow system. Receivers mark the appointment as no-show, stop arrival workflows, release or close resource assignments, update analytics, and trigger patient follow-up if the organization does that automatically.

Appointment identity in SCH is again critical. Patient context in PID helps the receiver show the missed appointment in the right chart or portal, and resource groups help the receiver close out room, staff, service, and equipment slots.

How to read the structure

S26 uses the common SIU_S12 structure. The same SCH, patient, and resource groups describe the appointment that was missed. Many systems also send notes or a local status code that distinguishes patient no-show from late cancellation, provider cancellation, or system error.

The no-show event is a scheduling status. HL7 Chapter 10 points out that patient-administration events such as A01, A04, A05, or A10 can represent arrival, while A03 or A09 can represent the end of an appointment. Do not try to infer all of that from S26 alone.

Implementation traps

The first trap is confusing no-show with cancellation. A cancellation stops a future appointment from happening. A no-show records that the scheduled appointment was missed. Those two statuses feed different reporting and follow-up.

The second trap is freeing resources too early. If the clinic has a grace period, the event should be sent after the local no-show decision, not merely at the appointment start time.

Reference notes

HL7 Chapter 10 scheduling describes S26 as a notification that the patient did not show up, useful for appointment status/statistics and freeing resources. Caristix, iNTERFACEWARE, and Rhapsody list S26 as the patient-no-show SIU notification event.